Method for forming concrete piles



Jan. 12, 1960 w. RYSER ETAL 2,920,455

METHOD FOR FORMING CONCRETE FILES Filed Nov. 16, 1955 3 Sheets-Sheet 1 I57 7' 1 as ill .5 I1

IN VENTORS A ORNEYS' Jan. 12, 1960 w, RYsER ETAL 2,920,455

METHOD FOR FORMING CONCRETE FILES Filed Nov. 16, 1955 3 Sheets-Sheet 3E17- g H 33 2: ;.3

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United States Patent-"Q 2,920,455 METHOD FOR FORMING CONCRETE PILESApplication November 16, 1955, Serial No. 547,241

1 Claim. (Cl. 61-57) This invention relates broadly to the production ofconcrete piles and in its more specific aspects it relates to a methodand apparatusv whereby poured-in-place concrete piles are rapidly andefficiently produced; and the nature and objects of the invention willbe readily recognized and understood by those skilled in the arts towhich it relates in the light of the following explanation and detaileddescription of the accompanying drawings illustrating what I at presentbelieve to be the preferred embodiments or mechanical expressions of myinvention from among various other forms, arrangements, combinations andconstructions, of which the invention is capable within the spirit andscope thereof.

In construction work where concrete piling is required it isconventional practice to drill a hole in the ground to the proper depthwith an earth auger and to then withdraw the auger whereupon the pile isformed by pouring concrete into the hole. Concrete piles are of courseused in many different ground formations and classes of earth and wehave encountered many difliculties'and inherent problems in formingpiles in the conventional manner, and our present invention is directedtoward and does solve the many undesirable aspects and operationalproblems which have heretofore caused the forming of piles to be a slow,expensive and relatively difficult construction process.

'In conventional methods of forming piles the nature of the soil inwhich the hole has been drilled may be such that after the auger iswithdrawn the wall of the hole will collapse or cave in so that the nextstep in the process of pouring the concrete may not be accomplished.When such a cave-in occurs it is necessary to re-drill the hole orremove the dirt in some way and to shore up, rei'n'force or stabilizethe walls so that the hole may be kept clear and the concrete poured toform the pile.

Various means have been devised for stabilizing the soil to preventcave-ins following withdrawal of the auger. For instance, treatment ofthe soil with stabilizing chemicals has been suggested and tried, andstructural apparatus for preventing cave-ins and collapse of the wallshave been used. However except in ideal soil conditions such methods andoperations are very difiicult and are obviously expensive and timeconsuming.

"'Our studies and experiments in this field resulted in the developmentof the concept which involves the use of the drill or earth auger itselfas the stabilizing medium for the wall of the hole into which theconcrete is to be poured. It will be recognized that this conception andthe method and apparatus whereby it may be practically carried out,eliminates the time consuming steps of removing the auger after the holehas been drilled, then stabilizing the walls of the hole if the soilwill permit and then pouring the concrete.

need for certain apparatus and materials which were required in thepractice of prior methods, and it ensures against cave-ins while priormethods were, at best, uncertain;

Not only does our concept involve the saving of time but it alsoeliminates the ice In practicing our method of producing poured-in-placeconcrete piles we do not remove the earth auger immediately followingthe operation-of drilling the hole to the proper depth, instead theauger is gradually withdrawn from' the hole as the concrete is pumped inthrough the auger itself. Thus, the auger forms at all times the wallreinforcing means for that portion ofthe 'hole which has not been filledwith concrete. It will be fully appreciated as the description of ourmethod and apparatus proceeds that the concept of slowly withdrawing theauger as the concrete is poured eliminates the need for certainheretofore required extra equipment and materials and reduces the numberof steps to be performed in forming concrete piles, and our inventiontherefore constitutes a substantial saving in labor, time and materialswithout sacrificing the strength or efiiciency of the finished pile,

Iu order to provide practical equipment to carry out our method of usingthe earth auger as the stabilizing or supporting means for the walls ofthe hole while pumping or otherwise causing concrete to flow through theauger and into the hole while withdrawing the auger as the hole isfilled with concrete, we evolved an earth auger of novel constructionand also supporting and operating equipment of an ingenious naturewhereby the efliciency of our operation is substantially advanced.

. The drill or earth auger which we have evolved is of generally tubularconstruction so that a duct or core is provided therethrough throughwhich the concrete flows into the hole, Since the auger which is used asthe sta bilizer for the walls of the hole is the one which has drilledthe hole in the ground it is provided with a cutting bit on one endwhich must be so designed that it will not obstruct the flow ofconcretefrom the drill into the hole. Because of the consistency of theconcrete the complete flow course provided in the drill must be designedfor free-and unobstructed flow of the concrete if eificient andsatisfactory results are to be obtained. We

have designed the bit of our earth auger so that it affords free flow ofthe concrete into the hole which the auger has drilled and we have alsodesigned the bit to act as a spreader for the concrete as it flows fromthe auger and into the hole.

It will be recognized that during the drilling operation it will benecessary that the duct or tubular core of the auger be kept free of theexcavated material so that the concrete may flow therethrough at theproper time. We

' have designed a bit or drill tip which functions in this desirablemanner for it deflects the excavated material radially outwardly awayfrom the lower outlet from the concrete flow duct through the auger toensure against such excavated material entering and clogging orobstructing the duct.

augeras a wall stabilizing medium and of forcing con-- crete through theauger as it is withdrawn from the hole which has been drilled thereby wehave devised a novel rig for supplying the concrete to the auger and forcontrolling the auger in all of its various operations in carrying outthe steps of our method.

Claims directed to the auger are not presented in this application butare included in our copending divisional 1 application Serial No.693,094.

With the foregoing general objects, features and results in view, aswell as certain others which will be ap parent from the followingexplanation, the invention consists in certain novel features in design,construction, mounting and combination of elements, as will be more fulland particularly referred to and specified hereinafter.

Referring to the accompanying drawings:

Fig. 1 is a view illustrating the rig and mobile equipment we may use indrilling holes and pouring concrete thereinto while following the methodwe have devised.

Fig. 2 is a view in elevation of the earth auger of this invention.

Fig. 3 is a view in elevation of the bit or tip of the earth auger withparts of the auger being broken away.

Fig. 4 is a view in elevation of the bit or tip of the earth augerrotated approximately 45 from the position illustrated in Fig. 3.

Fig. 5 is a view taken on line 55 of Fig. 3.

Fig. 6 is a front view in elevation illustrating parts of the rig andparticularly the mounting and arrangement of the concrete pressure part,drill table and air motor.

Fig. 7 is a side view in elevation of the parts of the rig illustratedin Fig. 6.

Fig. 8 is a plan view of the lower end of the earth auger particularlyillustrating the bit or tip of the auger.

In Fig. l of the drawing we have illustrated schematically the equipmentrequired in practising our method of constructing foundationsubstructures in place, such as poured-in-place concrete piles. Thisequipment may include a mobile crane 1 having the usual boom 3 extendingtherefrom. A superstructure, or framework 5 may be supported on theground adjacent the spot where the hole is to be drilled, thesuperstructure being positioned and controlled by the crane by means ofa swivel 7 to which lines 9 and 11 extending from the boom are attached.Leads or rails 13 (Fig. 6) are provided on the superstructure orframework 5 for a purpose to be hereinafter described.

We provide a sliding platform or elevator which is mounted on thesuperstructure 5 for movement therealong in either direction. Thissliding platform supports the earth auger in different raised positionsrelative to the ground, the mechanical means for operating the auger andthe concrete supply, tank, all as will be explained.

The sliding platform or elevator may consist of two vertically spacedfloors or supporting surfaces 15 and 17 which are connected together bybraces 19 to form a unitary supporting or elevator structure which isslidably mounted on the superstructure or vertical framework 5 by meansof shoes 21 adapted to slide on the leads or rails 13. The platform ismovably maintained in any desired position along the superstructure bymeans of a hoist line 23 which is connected to the platform or elevatorin any suitable manner, the hoist line extending over the top of thesuperstructure as at 25 and then to the crane where it may be Wound andunwound on a usual drum or the like at the will of the operator. Thus,by winding or unwinding the cable or line 23 the position of theelevator on the superstructure and the distance thereof from the groundmay be changed.

We have used the numeral 27 to designate the earth auger in itsentirety. The earth auger is formed with a tubular shaft or stem 29which extends through the platform 15 and 17 when the auger is mountedand supported in operative drilling position. The drill or auger stemextends upwardly above upper platform 17 where it is associated with anysuitable drill table 31 which is supported by the upper platform 17.

A concrete pressure pot 33 is supported from the upper platform 17 bymeans of braces 34 above the drill table 31 and is formed with a lowertubular concrete outlet 35 which is in communication with a swivel 37associated with the drill table and the upper end of stem or tubularshaft 29, The construction is of such nature that concrete may flow fromthe pot 33 through outlet 35 into the swivel 37 and into the upper openend or mouth of the shaft or stem 29 of auger 27. The concrete inconcrete pot 33 may be subjected to a head of pressure for insuringproper flow of the concrete from the pressure pot and into the drilledhole. Compressed air is generated by a compressor 39, the air beingcarried to the pressure pot by means of a flexible hose 41.

Compressed air from the compressor is also supplied to an air motor 43by means of a flexible hose 45. The air motor is mounted on platform 15and is adapted to cause rotation of the auger and is operativelyconnected therewith in any suitable manner, as by transmission 47 and achain drive 49. The equipment preferably includes a pressure pot loadingbucket 51 which is adapted to be hoisted in any suitable and usualmanner up the superstructure to the pressure pot for dumping its load ofconcrete thereinto. The raising and lowering of the bucket 51 may becontrolled by a cable 53 which extends from operating means in crane 1to pulley 55 at the base of the superstructure and up to and overpulleys 57 mounted on the superstructure.

The earth auger 27, which forms one of the novel features of ourinvention and is particularly useful in practising our method of formingconcrete piles though not limited to earth drilling operations followingthe method of our invention, comprises the hollow stem or shaft 29,which is open at both ends and is designed for free and unobstructedflow of concrete therethrough. Fixed on and extending upwardly from thelower end of shaft 29 to a point spaced below the upper end of. theshaft are flights 59 which function to remove the excavated material asthe auger is rotated by the air motor in a drilling operation. We havehad satisfactory results when using a shaft of approximately 5 LD. andapproximately A" plate flights at approximately 7 pitch. The edge of thelower flight 61 mounts a cutting plate 63 by means of bolts 65 and thecutting plate may be provided with a tapered leading edge 67 for cuttinginto the ground as the auger is rotated in a drilling operation.

We have used the numeral 69 to designate in its entirety the tip or hitof the earth auger. The tip 69 is mounted on the lower end of hollowshaft 29 by means of a collar 71 which encompasses the end of the shaftand is fixed thereto by welding or the like. The collar may be of splitring construction and if so the split should be welded after the collar71 is mounted on the lower end of shaft 29.

Fixed in any suitable manner, as by welding, to the collar 71, weprovide a pair of oppositely disposed and circumferentially spacedelongated vanes 73 and 75, which depend downwardly from the collar. Eachvane is inwardly curved or of arcuate formation downwardly to a pointwhere the ends thereof are notched and abut as at 77, the extending ends78 and 80 forming a fish tail point for the drill bit which breaks upany hard strata of material that may be encountered in the drillingoperation. The abutting ends of the vanes may be fixed together bywelding. The vanes are of downwardly tapering construction and thediameter of the lower end of the tip 69 is reduced relative to thediameter of the upper end. The forward or leading edge of vane is curvedinwardly as at 76 while the forward or leading edge of vane 73 is curvedinwardly as at 74'. The rear or pressure edge of vane 75 is curvedoutwardly as at 76 while the rear or pressure edge of vane 73 is curvedoutwardly as at 74.

A spreader plate 79 is welded to each of the vanes, the spreader plateextending between and in welded engagement with the vanes from a pointadjacent the abut ting tips thereof upwardly a distance. This spreaderplate, as will become apparent, functions as a structural member for thevanes and also as a spreader element for the concrete as it fiows out ofthe auger. Each vane is twisted or warped about a generally longitudinalaxis and in the same direction from their fixed points on the collar to5 thereby offset each longitudinal edge of one vane relative to theplane of rotation of one of the longitudinal edges of the other vane.This twisting distortion or warping of the vanes also causes theabutting ends of the vanes to be offset as at 81. Due to the warping ofthe vanes 73 and 75, as described, the leading edges 74 and 76 on thevanes, along substantially their entire lengths, are disposed radiallyinwardly relative to the trailing edges 74 and 76' of the vanes.Consideration, particularly of Figure 5 of the drawings, will clearlyillustrate that, as the auger is rotated in a drilling operation in thedirection of the arrow, the excavated material will be thrown radiallyoutwardly due to the unique distortion configuration of the vanes, whichrelatively positions the leading and trailing edges, as described. Thus,no excavated material will be forced or will otherwise accumulate in andclog the shaft 29, through which concrete is adapted to flow.

In order to facilitate the drilling operation we provide a number offins on each vane which extend radially outwardly therefrom. In theparticular embodiment illustrated in the drawing we provide three fins86 which may be welded to the vane 73 in vertically spaced relation.Each side fin is fixed to the vane at an angle or inclined downwardly ina forward direction so that its leading edge 88 is lower than itstrailing edge 90. Three generally similar fins 92 are fixed on vane 75,the lowermost of said fins being fixed in a plane below the lowermostfin 86 on vane 74 and the other fins 92 being alternately positionedhorizontally with respect to fins 86. The fins 92 are mounted at anangle so that each leading edge 94 is lower than each trailing edge 96.It will be recognized that due to this particular construction the fins86 and 92 will push the material up to the cutting edge 67 and onto theflights.

When it is desired to form poured-in-place concrete piles, in accordancewith our method and with the apparatus we have devised, thesuperstructure 5 is posi.

tioned adjacent the site in which the hole is to be drilled,superstructure being so positioned that the sliding platform or elevatorwill be directly over the spot Where the hole is to be drilled. It willbe understood, of course, that all of the operating equipment isproperly mounted on the superstructure and operatively connected withthe crane and compressor. The auger is then rotated by the air motor andthe hole is drilled to the proper depth, whereupon the rotation of theauger is stopped and the auger is maintained in its position; within thehole which it has just drilled. With the auger in position within thedrilled hole, it will be evident that it acts as a reinforcing orstabilizing member preventing collapse or cave-in of the walls of thehole. Thus, it is not necessary when following the teachings of ourmethod to apply any additional stabilizing medium to the walls and wehave therefore eliminated steps in prior art methods and we have alsoeliminated the need for extra equipment.

In designing the tip or bit of the auger, it was necessary to form allcomponents of the tip so that they would not obstruct the concrete as itflows out of the hollow shaft and past and through the tip. It wasessential, of course, not to sacrifice the cutting and operatingcharacteristics of the tip in order to afford free unobstructed flow.With these prerequisites in mind, we also had to design the tip so thatit would throw the excavated material radially outwardly, rather thaninwardly, to thereby avoid clogging the shaft or the tip with excavatedmaterial which would hinder concrete flow. We have evolved a tip whichaccomplishes all of these purposes. It presents no obstructions againstflow of concrete. It cuts efliciently and it throws the excavatedmaterial radially outwardly and upwardly where it is caught by thespiral flights 59 and carried upwardly out of the hole. As the drillingoperation proceeds, the blade 63 cuts into the ground radially,outwardly of the hole cut by vanes 73 and 75. Since the interior flowduct for concrete provided by shaft 29 is Smooth and presents noobstructions whatsoever against crete, as described, while using a 15/2" diameter auger to dumped into the pressure pot 33. It is desirablethat the charge of concrete be an amount which is predetermined and issuflicient to fill the hole with concrete 86 to a level, such as 87(Fig. l), at which time the auger is fully withdrawn from the hole.

When the pressure pot has been loaded with the concrete and covered inany suitable manner, it may be subjected to a head of pressure fromcompressor 39 through hose 41 to force the contained concrete downwardthrough tubular shaft 29 and out the lower end thereof and past the tip69 and into the hole. As the concrete flows out of the shaft, it willnot be obstructed or hindered by the tip for the reason that allcomponents thereof, which are more or less in alignment with theinterior of the shaft are spaced a distance from the outlet therefromand the closest is the upper edge 89 of plate 79, which is relativelythin and a nonobstructive surface. Thus, the concrete will not clog upas it exhausts from the shaft outlet and may freely flow radiallyoutwardly between the vanes 73 and 75 and into the hole.

As the concrete is forced from the pressure pot through the shaft andout the tip or bit, the auger unit is withdrawn at a speed to keep thetip or hit below the surface of the deposited concrete. As the auger iswithdrawn, it is not rotated and the spreader plate 79 serves to divideand spread the concrete flowing through the bit. The Withdrawal of theauger is of course operated from the crane by means of the hoist line23.

When all of the concrete is emptied from the pressure pot into the hole,the concrete will have reached the level 87, leaving an unfilled uppersection 91 in the hole. At this time, when the hole has been filled withconcrete to the level 87, the auger is fully withdrawn and a cover maybe placed over the hole and the waste excavated material on the spiralflights may be shaken loose. The cover is then removed from the hole andthe auger is lowered back in. the hole to remove the top one foot ofconcrete, only if soil or other deleterious matter has fallen back intothe hole on the concrete. If no such matter has fallen back into thehole, or, after it has been removed with the auger, then a reinforcingcage 93 is lowered into the unfilled portion of hole 91 and the holefilled with concrete in any conventional manner.

Merely as one example from among many of the dimensional characteristicswhich the auger may have, we have successfully drilled the holes andpoured the conproduce a 16" hole, the ID. of the shaft 29 being 5". Theoverall length of the tip or hit being 13 /2, while the diameter of thelower end is approximately 5 /2" (shaft O.D.), while the diameter of thedrag edge is 6% (OD. collar 71). The upper edge 89 of spreader plate 79is approximately 4" below outlet of shaft 29.

It is to be understood that the mechanical equipment and operating meansfor positioning and controlling the auger may be changed and still fallwithin the spirit and scope of our invention for the rig and equipmentillustrated in Figure l is included merely by Way of example and not aslimiting our invention to use with the particular equipment disclosedfor operating and controlling the earth auger.

It will now be recognized that we have devised a rapid and efficientmethod of forming poured-in-place concrete piles and also the equipmentwhereby the method may be carried out. Our method substantially reducesthe time required to form piles of this character as well as 7eliminating much equipment and materials formerly required.

We claim:

The method of forming poured-in-place concrete piles which comprisesdrilling a hole in the ground with a tubular auger open at its lower endand provided with a bit having openings therein and said auger beingprovided with spiral flights, forcing the excavated material radiallyoutwardly relative to the bit during the drilling operation, maintainingthe interior of the tubular auger free of earth during the drillingoperation, drilling into the earth whereby a portion of the earth on thespiral flights is removed from the hole, maintaining the auger at thefull depth of the hole at the conclusion of the drilling operation and,when the hole has been drilled to the proper depth, injecting concreteinto the auger at a pressure only sufficient to cause flow of theconcrete through the auger and past the bit into the hole whilesimultaneously applying vertical lifting forces to the upper end of theauger to gradually non-rotatively withdraw the auger and the remainingportion of the earth on the spiral flights from the hole.

References Cited in the fileof this patent UNITED STATES PATENTS HeathMar. 31, 1868 Philips et a1 Feb. 12, 1884 Densmore Sept. 26, 1899 ShumanFeb. 23, 1904 McCormick Feb. 11, 1913 Tufts Nov. 8, 1921 Powell Jan. 3,1928 Rea Mar. 21, 1933 Zerbe Apr. 3, 1934 Montee Dec. 10, 1935 GrahamDec. 22, 1942 Patterson Jan. 3, 1956 FOREIGN PATENTS Germany Dec. 28,1882 Austria July 10, 1914 France Dec. 22, 1954

